a) 35 x 2 x 9 x 5

= (35 x 9) x (2 x 5)

= (35 x 10 - 35) x 10

= (350 - 35) x 10

= 315 x 10 = 3150

b) 24 x 71 + 71 x 75 + 71

= 71 x (24+75+1)

=71 x 100

= 7100

giúpppppppppppppppppppppppppppppppppppp

\(\left(26-3x\right):5+71=75\)

\(\left(26-3x\right):5=4\)

\(26-3x=20\)

\(3x=6\)

\(x=2\)

(26-3x):5+71=75

(26-3x):5=4

26-3x=20

3x=6

x=2

a. (9x + 2).3 = 60

<=> 9x + 2 = 20

<=> 9x = 18

<=> x = 2

b. 71 + (26 - 3x):5 = 75

<=> (26 - 3x) : 5 = 4

<=> 26 - 3x = 4/5

<=> 3x = 26 - 4/5 

<=> x = 42/5

c. 2^x = 32

<=> 2^x = 2⁵

<=> x = 5

d. (x - 6)² = 9

<=> x - 6 = 3

<=> x = 9

a) \(\left(9x+2\right)\times3=60\)

\(\Rightarrow9x+2=60:3\)

\(\Rightarrow9x+2=20\)

\(\Rightarrow9x=20-2\)

\(\Rightarrow9x=18\)

\(\Rightarrow x=18:9\)

\(\Rightarrow x=2\)

Vậy x = 2

b) \(71+\left(26-3x\right):5=75\)

\(\Rightarrow\left(26-3x\right):5=75-71\)

\(\Rightarrow\left(26-3x\right):5=4\)

\(\Rightarrow26-3x=4\times5\)

\(\Rightarrow26-3x=20\)

\(\Rightarrow3x=26-20\)

\(\Rightarrow3x=6\)

\(\Rightarrow x=6:3\)

\(\Rightarrow x=2\)

Vậy x = 2

c) \(2^x=32\)

\(\Rightarrow2^x=2^5\)

\(\Rightarrow x=5\)

Vậy x = 5

d) \(\left(x-6\right)^2=9\)

\(\Rightarrow\orbr{\begin{cases}x-6=3\\x-6=-3\end{cases}}\Rightarrow\orbr{\begin{cases}x=9\\x=3\end{cases}}\)

Vậy x = 9 hoặc x = 3

_Chúc bạn học tốt_

a) (9x+2).3=60

       9x+2  = 20

           9x  = 18

             x  = 2

b) 71 + (26-3x) : 5 = 75

   (26 - 3x) : 5         = 4

    26 - 3x                = 20

          3x                  = 26 - 20

            x                 = 6 : 3

            x                  = 2

c) 2^x = 32

   2^x  = 2⁵

     x = 5

d) (x-6)² = 9

   (x-6)²  = 3²

      x - 6 = 3

         x =  9

bao đúng bn nhé

=> 26 - 3x = 75 - 71

<=> 26 - 3x = 4

<=> 22 = 3x

<=> x = \(\dfrac{22}{3}\)

Vậy ...

71 + (26 - 3x) = 75
26 - 3x = 75 - 71
26 - 3x = 4
-3x = -22
x= -22/-3
=> x = 22/3
Vậy...

\(71+\left(26-3x\right)=75\) 

   \(71+26-3x=75\) 

                   \(3x=71+26-75\) 

                   \(3x=22\) 

                     \(x=22:3\) 

                     \(x=\dfrac{22}{3}\)

<=> (26-3x):5=4

<=> 26-3x=20

<=> 3x=6

<=> x=2

vậy x=2

đc đấy 

nhưng tôi làm xong tc rùi

x = 2 nha , k

bạn có chép sai đầu bài ko

a)(9x+2)x3=60

        9x+2 =60:3

        9x+2  =20

              9x =20-2

              9x=18

                x=18:9

                 x=2

a,x=2

b,x=2

c,x=9

o phan a 

(9x+2)*3=60

9x+2=20

9x=18

x=2

o phan b

71+(26-3x)/5=75

(26-3x)/5=75-71=4

26-3x=4*5=20

3x=26-20=6

x=6/3=2

vay x=2

o phan c 

(x-6)^2=9

(x-6)^2=3^2

=>x-6=3

=>x=9

vay x =9

ở phần d 

1+3+.....+x=465

=>(x+1)*(x-1)/2+(x+1)=465

=>(x+1)*(x-1)/2

Câu 1:71+(26-3x):5=75

=>(26-3x):5=75-71

=>26-3x=4*5

=>3x=26-20

=>x=6:3

=>x=2

Câu 2:3636:(12x-91)=36

=>12x-91=3636:36

=>12x=101+91

=>x=192:12

=>x=16

Câu 1 :\(71+\left(26-3xX\right):5=75\)

\(\left(26-3xX\right):5=75-71\)

\(\left(26-3xX\right):5=4\)

\(26-3xX=4x5\)

\(26-3xX=20\)

\(3xX=26-20\)

\(3xX=6\)

\(X=6:3\)

\(X=2\)

Câu 2 : \(3636:\left(12xX-91\right)=36\)

\(12xX-91=101\)

\(12xX=101+91\)

\(12xX=192\)

\(X=192:12\)

\(X=16\)

Câu 1:

\(71+\left(26-3x\right):5=75\)

\(\left(26-3x\right):5=75-71\)

\(\left(26-3x\right):5=4\)

\(26-3x=4\times5\)

\(26-3x=20\)

\(3x=26-20\)

\(3x=6\)

\(x=6:3\)

\(x=2\)

Câu 2:

\(3636:\left(12x-91\right)=36\)

\(12x-91=3636:36\)

\(12x-91=101\)

\(12x=101+91\)

\(12x=192\)

\(x=192:12\)

\(x=16\)

d) 71 + (26 – 3x) : 5 = 75

(26 – 3x) : 5 = 75 – 71

(26 – 3x) : 5 = 4

26 – 3x = 4 . 5

26 – 3x = 20

3x = 26 – 20

3x = 6

x = 6 : 3 = 2

Vậy x = 2

Lời giải:
a.

$(x-15).27=0$

$x-15=0:27=0$

$x=15+0=15$

b.

$23(42-x)=0$

$42-x=0$

$x=42$

c.

$(9x+2).3=60$

$9x+2=60:3=20$

$9x=18$

$x=2$
d.

$71+(26-3x):5=75$

$(26-3x):5=75-71=4$

$26-3x=4.5=20$

$3x=26-20=6$

$x=6:2=3$